Silica-Based Basic Sorbent for Acid Gas Removal
Solution Overview
Problem
Current emission control strategies for acidic gas species like HCl, SO2, and SO3 are inefficient and costly, with sodium-containing sorbents being expensive and prone to fouling, while hydrated lime reactions are less efficient, necessitating a more effective sorbent for acid gas emission control.
Innovation Solution
A sorbent composition comprising silica (SiO2) and a basic inorganic solid, such as calcium hydroxide, with a hygroscopic component that maintains a moist environment for enhanced acid gas absorption, eliminating the need for humidification and providing improved surface area and pore volume for efficient acid species capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If sodium-containing sorbents are used for acid gas removal, then acid gas capture efficiency is improved, but cost increases and equipment fouling occurs
Solution Approach 1:
The patent changes the chemical composition parameters by using calcium-based sorbents with specific Ca/Si ratios (1:1 to 4:1) and controlled moisture content (5-20%), optimizing the physical and chemical properties to achieve high acid gas capture efficiency without the fouling issues associated with sodium-containing sorbents
Solution Approach 2:
The patent creates a composite sorbent material combining calcium oxide or calcium hydroxide with silica, forming a composite structure that leverages the high reactivity of calcium-based compounds for acid gas capture while silica provides structural stability and prevents equipment fouling
2Ease of manufacture
If hydrated lime is used for acid gas removal, then cost is reduced, but reaction efficiency decreases
Solution Approach 1:
The patent optimizes the moisture content parameter to 5-20% and controls the Ca/Si ratio between 1:1 and 4:1, transforming the physical state of calcium-based sorbents to enhance reaction efficiency while maintaining cost-effectiveness compared to traditional hydrated lime
Solution Approach 2:
The patent utilizes the porous structure of the calcium oxide/calcium hydroxide-silica composite to increase surface area and active sites for acid gas reactions, thereby improving reaction efficiency while keeping the sorbent cost-effective
3Productivity
If silica-containing sorbent with controlled moisture is used, then acid gas absorption is enhanced, but sorbent formulation complexity increases
Solution Approach 1:
The patent establishes specific parameter ranges for moisture content (5-20%) and Ca/Si ratio (1:1 to 4:1) that optimize acid gas absorption efficiency while providing clear formulation guidelines that prevent excessive complexity in sorbent preparation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The sorbent composition achieves improved HCl capture and reduced environmental impact by maintaining a locally moist environment, offering economic, processing, and performance advantages over conventional sorbents, with enhanced efficiency compared to trona and hydrated lime.
Implementation Method 1
B is a hygroscopic solid at a preferred water to solid molar ratio of about 0.1 to about 6
Implementation Method 2
basic materials are injected into the flue gas stream to contact the gas and neutralize acid gases, including hydrogen halides, SO2, SO3
Data Source
AI summary
An acid gas sorbent composition is disclosed. The composition comprises a compound having the following formula: (SiO2)x(OH)yF.B wherein F optionally exists and said F is at least one of the following: a functionalized organosilane, a sulfur-containing organosilane, or an amine-containing organosilane; and wherein B is a hygroscopic solid at a preferred water to solid molar ration of about 0.1 to about 6, and more particularly, B is a basic inorganic solid including, but not limiting to, alkali to alkali-earth metal oxides, hydroxides, carbonates, or bicarbonates, containing at least one of the following metal cations: calcium, magnesium, strontium, barium, sodium, lithium, potassium, cesium, lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, scandium, ytterbium, yttrium, or erbrium; wherein the molar ration of y/x is equal to about 0.01 to about 0.5.